The collagenolytic activity of tumor cells with graded degrees of malignancy will be examined, with the aim of correlating the degree of invasiveness with enzymatic activity. We are currently isolating and characterizing the collagenase found in tumor cells. We want to determine whether a precursor exists of tumor collagenase and what the relationship of the activation of this postulated precursor has with the degree of malignancy found. The biological balance of a postulated zymogen of collagenase, its activator and resulting enzyme and its relationship to the onset of malignancy will be ascertained. We have isolated what we consider to be "family" of low molecular weight cationic proteins which function as inhibitors of collagenase. The role of these molecules in connective tissue metabolism in normal and disease states is under investigation.